Engineering and manufacturing industries

Why voltages re still a touchy subject: the issue of touch voltages is one which continues to confuse electrical engineers who should know better

Article Abstract:

Protection by earthed equipotential bonding and automatic disconnection of supply is the most commonly used protective measure against indirect contact. 'Touch voltages' are deemed safe in the 16th Edition of the IEE Wiring Regulations. However there are still misconceptions about touch voltage, such as it only occurs between exposed conductive parts and extraneous conductive parts. Misconceptions surrounding separate installations which are part of TN or TT systems are discussed.

LED to safety

Article Abstract:

UK-based Chloride Safety Systems has developed a range of safety signs which are illuminated by light emitting diode (LED). The signs are cheaper to maintain and run, reducing the need to change light bulbs whilst saving on energy costs. The signs are easy to install, being pre-wired boxed sets which can be accessed through a rear trap door should there be a problem. The signs are suitable for use in hospitals, schools and other large premises.

Image problem

Article Abstract:

The BSRIA Application Guide AG17/97 Safe thermal imaging of electrical systems document provides information about how to use thermal imaging techniques in electrical equipment design. Thermography is used to determine heat loss where electrical faults occur in mechanical connections. A variety of testing equipment is available to enhance the safety aspects of design.